Mechanism for varying the setting of an object in accordance with conditions as established by the setting of the object



May 23, 1950 M. ADAMS 2,508,441

MECHANISM FOR VARY NG THE SETTING OF AN OBJECT IN ACCORDANCE WITH CONDITIONS AS ESTABLISHED BY THE SETTING OF THE OBJECT Filed Feb. 4, 1947 INVENTOR. WALCOTT M. ADA/W5 ATTOQ/VEY Patented May 23, 1950 U-iN l TED S TAT ES PATENT OFFICE MECHANISM FOR VAIVYING THE SETTING OF AN OBJECT IN ACGORDANGE CONDITIONS AS ESTABLISHED "BY THE ESETTING OF THE OBJECT WalcottM. Adams,'New I rk, ,NJZ.

.' tApplicationFbruary 4, 1947,1SeriaPN 00.726387 6 Claims.

.- My :invention ,relates -.to mechanism ;for' vary- ,ing {the setting ;of an object in accordance with .conditions as established by the setting of the object adapted flto control any function .where the -effect can be indicated electrically, :pneuimatically, =hydraulically ,or by :gravity.

(More specifically imy invention provides conitrol .-mechanismeso ,constructed and arranged as to .abe automatic ,intoperation, pin that .any detparture ifrom normal twill lbeindicated and .in-

sstrumentalities ,will be .set into operation to fiiiestore conditions :to .normal the speed ofcorrection being proportional to deviation, with no "-dead. ;zone and -withino-shiftiin control ,point.

As an. illustration of ,oneapp'lica'tion of my invention and Jfor ..clarity ,of description, ;but r. not

.by wayiofflimitationfl will describe .myv invention tasiapplied .to boilerior furnace air ifiowcontrol. The (single .,.flgure.,.of .the drawing is a diagram illustrating aniair jflow control embodying my invention.

i Referring to .the drawingsin detail, i2.designates aboiler equipped with damper ,6, which in -the illustration hereinafter ,.described is the ,objectithesettingnf which is to. be varied. This Jdampenis adapted (to be rotated in ,one direcgin theflueigasesfthe smalleris the amount-of "light jialling upon the light-responsive element ."llLiand the clearer the haze in the hue .gases thegreaterj is theamountdiflig'ht falling upon l 0.

' I4 designates an indicator,'herein shown .as a .microammeter, the movableelement or needle of which is ,Qdes'ignated 1,6. This, indicator f is ,conlnectejd electrically ato the light-responsive ele- 'mentlfl sothat the needle l.6 .indicates.,haze

.conditions. in..the flue A.

I "[8 is .1. a ,potentiometer ,;'for adjusting the cur- .,rent, passing through the winding ,of indicator .Il4 to provide fforinitialsetting of-the equipment so that when desirejdhaze .conditions exist in fflue 4 ;the needle Il6 .will stand at the neutral oncontrdlpoihtN on'the scale of the indicator. As willbe brought out hereinafter, the position of the neutral point iNv-"on the indicator dial -varies with difierentiinstallations.

.;element or striker ..20 which is pivoted vat 1&2,

which is ofiset with respect to the pivot v2,410! the needle |6as-willbe scen -from thedr-awings.

The-striker 2,0 is moved back and forth across the face of :indicator l4:bystriker-actuating-bar 26 which: is pivoted at=28 and driven by constantly rotating motor 30.

' Thestriker-actuating bar is provided with .two pins 32 and 34, one at ea-chiextremity-of thebar. These ,pins .areequidistant fromtheaxis of rotation :28 of the bar and are adapted to engage a-cam =28 which attached to the striker and extends above and below the pivotal ,point ,2!

thereof. The striker actuating bar isalso-provided with pins-36 and 38 intermediate the pins 432 :and v34 set --eq11idistant from axis of rotation 28, but nearer this axis ,thanthepins Hand .34. The pins 36.-and =38 ,areradapted to engage ,the

cam 29 of theistrikenbelow-the pi-votalpointlli thereof.

From the description thus far given -it willLbe seen that with the, striker actuating bar 26 rotating in :.the direction of .the ,arrows on the drawings, .the pins carriedby ,thebar Willemgagethecam 29in .thefollowing order: 36,131, 38 and .34. ,.-By,reason,of ,the fact that ,thepins 36 and 38 engage the ,cam 29 'belowathepivot ,22 of the striker, .andthepins ,32 and 3.4 engage this cam above the pivoti22, thestriker will be swungibackland forthacross the dial of the indicator l4. Itwill beunderstood thatthisoperation 1 is i continuous, the, circuit ,of .the motor ,3!)

always being closed.

The tip of the indicator .needle .I 6 ,is equipped with-ametal sleeve. while ,thetipof the striker 20 is equipped with a permanent magnet 44.

Consequently as the striker sweeps across the .indicator.it..will carry the needle lwithlit. Under certain conditions the strikerrand needlecarry current, andbyproviding the magnetimarrangeiment ust ;referred .to, chattering of the 'two ,;members. an d arcingiare prevented. ,Byofisetting the pivots for theistriker and indicator .the

striker magnet moves upwardly of the needle at either side of centralsposition. This provides a .wiping ,actionand a more certain contact be- ,tweenstriker and needle,,and :also a means for disengaging the magnetic contactat the end "of the back stroke as the magnet slidesoff the, sleeve 42 allowing .the needle to swing free.

The objectio'f this arrangement, as will appear amore,iullyhereinafter is to eifect, operation of Jthemotor 8, in ;one,:direction or the other, when the ,needle .;I 6 of "the indicator :is in other than neutral 'or' normal position. When the indicator needle stands at neutral N, flue conditions are normal and member 6 should not be adjusted. Any other position of the needle indicates either an abnormal or subnormal condition, the flue gases being either too dense or too clear, requiring that the damper be moved toward opened position or closed position as the case may be.

The bar 26, hereinabove referred to as the striker-actuating bar, has a function other than actuating the striker arm 20. from the drawing a cam 46 is mounted on the axis of rotation of the bar. This cam is provided with rises 48 and 50 set 180 apart. The cam is adjustably mounted to permit of initial setting to suit varying conditions. Extending into the path of the rises 48 and 50 of the cam, so as to be depressed thereby as the cam rotates, is the free end of a switch-actuating spring-arm 52. The other end of this switch-actuating arm is anchored adjacent a switch 54 comprising a spring-contact arm 56 and cooperating fixed contacts 53 and 60. The contact arm 56 is arranged to deflect itself into engagement with a fixed contact 58 when the switch-actuating arm 52 is riding upon either of the two dwells of the cam 45, and to be deflected by the arm 52 into engagement with a fixed contact 60 when the switchactuating arm 52 is deflected by either of the two cam rises 48 and 50.

62 designates a control relay the circuit to the coil of which is adapted to be closed when the striker is in engagement with the indicator needle I6.

The relay 62 controls two spring switch arms 14 and 16. With the relay-deenergized these switch arms spring into engagement with fixed contacts '18 and 82, respectively. Energizing of the relay coil pulls these arms out of engagement with the contacts mentioned and into engagement with the flxed contacts 80 and 84, respectively.

I find it desirable under some conditions to employ signal lamps with my control, one of which is shown at 86 and one function of the relay 62 is to control the circuit of this lamp.

92 designates another relay the circuit of which is closed when the arm 56 of switch 54 is closed on contact 60 due to depression of switch-actuating arm 52 by cam 46.

This relay when energized is adapted to aorection of rotation of the reversible damper motor Normal Let it be assumed first of all that proper haze conditions exist in the flue 4. In other words normal conditions exist, in which event the indicator needle I6 will stand at neutral point N and while the striker 20 is moving back and forth across the dial oi the indicator because of the constantly rotating motor 30, there should .be no operation of the damper-control motor .8 nor should either of the lamps 86 and H0 be 7 energized. i

As will be seen iii:

Under assumed conditions, with indicator needle at N, as the striker 20 starts on its movement to the right as viewed in the drawing, the rise 58 of cam 46 will depress the spring arm 52 to close switch arm 56 on fixed contact 60, which closes the circuit to the relay 92. This circuit may be traced from current source, conductor 64, switch arm 55, contact 60, conductors 92 and 94, relay 92 to ground 96. The circuit of the lamp 86 is open at contact 58 of switch 54, and that of lamp III} is open at contact 80 of the switch controlled by relay 62, the circuit of this relay being open at tip oi? striker arm 44 and also open at contact I82 of the switch controlled by relay 92. The motor lead H8 of motor 8 is open at contact I04 of the relay 92, and the lead I26 of the motor 8 is open at contact 84 of the relay 62.

By the time the striker has moved into position to pick up the indicator needle I6 at N, the rise of cam 46 has moved away from arm 56 allowing switch arm 56 to move out of engagement with contact to open the circuit of relay 92, the switch arm 56 moving into engagement with fixed contact 58 so that a circuit is closed to lamp 85 through conductor 88 only as far as contact 78 which contact is open by action of relay 62 whose circuit is closed by contact of the striker 20 with the needle I8. This relay circuit may be traced by way of conductors 64 and 66, relay 62, conductors 68 and I0, striker arm 20 and indicator needle I6 to ground 12. Again there is no movement of motor 8, because common motor lead I24 is open at contact 82 of relay 62 and at contact I08 of relay 92.

When the relay 92 was de-energized and relay 62 was energized as just described, a holding circuit was established for the relay 62, which may be traced from current supply source conductors 64 and 66, relay 62, conductors 68, I32, contact I02, and switch blade 98 of relay 92, conductor I I6, contact 8!! and switch blade I4 of relay 62 to ground 90.

The striker will continue to carry the needle across the indicator dial to the end of the travel of the striker at the right hand end of the dial, at which point the striker is disengaged from the pin 36 or 38 as the case may be. Immediately the pin 32 or 34 engages the striker to return it to its original position to the left of the indicator dial, the indicator needle, due to magnet 44 is carried back across the indicator dial to a point beyond the scale, when, due to the different axes of the needle and striker, the magnet slides upward off the sleeve 42 allowing the needle to swing free. The relays remain in their described position, relay 62 energized and relay 92 ale-energized until the striker arm returns to its starting position and depresses the switchactuating spring arm 52.

The holding circuit above referred to serves two purposes. One function is to reduce to a minimum the are between the striker and needle as they separate.

The other function of this holding circuit is to ensure that the circuit of the motor 8 will remain open after the needle and striker separate near the end of the back swing and to reset the relays simultaneously at the beginning of the next cycle without placing current on the motor 8.

Abnormal Let us assume now that the indicator needle I6 is to the right of neutral N. Under this condition sition-indicating normal haze conditions.

the haze in tine 4 is too dense,- abnormal; so that it is-desiredto move the-dampertowardopencd position and energize lamp 86 as the striker star-ts on its movement to the right, therise' oicamlfi willdepress the spring arm 52 to close switch arm 56 on fixedcontact 69, which closes the circuit torelay 52, by way of conductor 64,- switch arm 55,-contact-60, conductors Stand 94; relay $2 7 to ground 96. This will break-the contact of switch blade 98 with contact 12 thus breaking the holding circuit for the-relay 62 at contact 8i] and switch blade 14. There is no action ofmotor 8 at this moment in that motor lead H8 is broken at contact M4 and swltc'hblade 100' of the-switch controlled by'therelay 92;. which is nowenergized, while motor *lead I26 isi-zop n at switch blade I6 and contact 84 of theswitch controlled by relay 62'; -There=are no lampsenergized because circuit of lamp 88 isopen' at the contact 58 and switch blade 56 or the switch 54 and the circuit of lamp Hi! is open at contact 80" and "blade 14 of the switch controlled 'by' relay 62. As soon as the striker passes the neutral point on the indicator dial the riser of cam 46 will ride off the spring arm 52 permitting switch arm 156 of switch 54 to return into engagement with fixed contact 58,- so that a circuit is-now closed to the lamp 86. 'Theci rcuit to relay 92 is broken at contact 6!! and switch blade 56 oI-switch 54.

tact I04 and blade 1B0 ofthe switch controlled byrelay 92 and at contact BZandIG'of the switch controlled by relay'62, both relays at this moment being de-energiz'ed. This condition continues until the striker picks up the indicator needle. At this instant a circuit is closed to the relay 62, byway of conductors, fidthrough the relay, conduct0rs'68,'10 striker 20, indicator needle I6 i ground 12. This opens the circuit of lamp 86 and opens the circuit of the motor 8 at {switcharm It and contact 82 of the-switch controlled by relay 52.

This condition will continue until" the striker has swung all the way'a-cross the dial of'the indicator and back to its original position, and the needle oi the indicator has returned to proper indicating position, it being seen that theholdin circuit of the relay 62 is still maintained so that relay 62 remains energized even though thestriker and indicator needle are no longer engaged.

After the striker has moved'all the way across the indicator and returned toits initialposition and the indicator needle hasbeen released to return to indicating posi-tion,- the cycle of operation just described will be repeated, assuming that haze conditions are still-abnormal. On the other "band, should haze conditions during this cycle 1 l6 moves toposition indicating abnormal 'haze conditions until the needle returns toneutral po- On the contrary, the motor 8 is operated. intermittently,

actually only during the time it'takes for the striker to move from the neutralpoint N until it engages the indicator needle; 'This tirne varies of course depending upon the degree of abnormal :density of the haze int-he-flue. The denser the haze-the more the'ne'edle I6 isndeflected -and the ionger'the time required for thestriker to en- :gage theneedle. This feature is oi importance in 1 that tit-provides a movement of motor 18 .Io'r. each cycle .of operation which is proportional: tothe deviation of; the needle |.6,..that is, thenet speed of motor 8 (movement per :unit of time) is proportional to deviation of IS. This avoids too much movement .or overadjustment of the damper. For. example, suppose that .under the abnormal haze conditions assumed the circuit of the motor 8 .remainedclosed throughout the time the indicator needle'was ofi the neutral point. Under thesecircumstances it might VGI'YWGH be that the damper would have been opened to its maximum, whereasbutra slight movement toward closed position would berequired. In that case haze con.- ditionszwould be subnormal, necessitatingmovement oithe damper, toward closed position, so that there "would be constant overrunning of the motor 8,1irs-t inonedirection and then. the other, the net result of which would: be that the damper never would-be properly set. By arranging the control: sothat thev damper is moved at a net speed proportional to deviation of the indicator needle this over-adjustment .is avoided. It will be appreciated also that there is'necessarily a lag between movement of the damper and a change in flue conditions, and that by arranging the control as described I overcome this lag, in that in .efiec-t I-move the damper slightly toward open position and'then wait until this effects a change in the desired direction in the haze'conditions in the il-no; beiore moving the damper further, which furthermcvement, as a matter of fact, may or may -I- 10t-b e necessary.

Subnormal 6 toward closed position and to energize the lamp The striker starts to the right and switcharm 56 is depressed into engagement with-contact 60, so that a circuit is closed to relay 92 and the holding circuit to relay 62 is opened. Conse quently neither lamp at this moment is energized, and both leads of the motor 8 are open so that there is no-motor action.

When the striker has swung into engagement with the indicator needle, relay 62 will be energized. At-this instant both relays 62 and 92 are energized. With both relays energized, and. striker arm and indicator needle in engagement, and both to the left of neutral N, a circuit is closed to the lamp Ill] and the circuit of motor 5 is closed in a direction to rotate the motorto the ri ht to move the damper toward closed position; This condition exists until the striker arm and the indicator'needle reach neutral N. At this point the circuit of relay 92 is opened, thecircuit of the motor 8 is open and the circuit of lamp I It is open. Therefore the motor stops'a'nd there are no lamps lighted.

- Thi condition will continue to the end of the striker swing. and throughout its return; If fiue conditions are still subnormal this cycle will be repeated until flue .conditions have been restored to normal.

that Izhave provided mechanism for. controlling the setting of an object in accordance with certain indicated conditions. In the illustration described this object is a damper and the indicated conditions are the haze conditions in a flue. It is to be distinctly understood that application to boiler or furnace air flow is purely illustrative. Obviously my invention is equally applicable to air conditioning equipment, wherein it may be desired to introduce some foreign material into the air being supplied to a room. Then again this same control is useful for controlling the pressure in a vessel by controlling the fire, in which event the lamp and cell hereinabove referred to could be dispensed with and the pressure indicated electrically or by a, pneumatic gage. The same control could be employed-in heat treating processes where operation of the control mechanism could be initiated by thermocouple. My control is useful for controlling the rate of flow of a liquid or gas into a reservoir or receiver to maintain a desired level or pressure therein as indicated by a suitable indicator.

These applications of my control all come within the scope of my invention. In all cases there is required an indicator of some sort for indicating desired conditions and the condition existing at any instant, and in all cases there is an object which must be adjusted to restore conditions to normal, and in all cases when the indicator indicates any condition other than normal, instrumentalities will be set into operation to vary the setting of the object to be adjusted.

It is to be understood furthermore that changes may be made in the details of construction and arrangement of parts hereinabove described within the purview of my invention.

What I claim is:

1. In mechanism of the class described including an object the setting of which is to be varied, the combination of an indicating device having a movable element the position of which varies with respect to a neutral point on the indicating device with changes in condition as established by the setting of the object, an intermittently operated electric motor for varying the setting of said object, an oscillatable striker adapted intermittently to engage said movable element, a rotating actuator for oscillating said striker, a double throw switch comprising a spring arm for closing the switch in one direction, a cam carried by said actuator and adapted intermittently to engage said spring arm for closing said switch in the opposite direction, a relay the circuit of which is closed when said actuator is-moving the said striker toward the movable element of the indicating device and said cam i holding the double throw switch closed, a second relay, a holding circuit therefor, a switch in said holding circuit which opens upon closure of the circuit of the first mentioned relay, further movement of said actuator sufficient to move the striker past the neutral point of the indicating device rotating said cam out of contact with the arm of the double throw switch permitting the switch to close in the opposite direction, whereby upon the striker passing the neutral point both relays will be deenergized, a pair of motor control switches closable upon de-energization of said relays to close the motor circuit to alter the setting of the object in a direction to restore conditions to normal, and a circuit for the second mentioned relay adapted tov be closed when the striker moves still further into contact with the movable element of the indicating device, whereby said relay will open the motor circuit, thereby to provide a movement of said motor proportional to the deviation of the movable element of the indicating device.

2. In mechanism of the class described including an object the setting of which is to be varied, the combination of an indicating device having a movable element the position of which varies with respect to a neutral point on the indicating device with changes in conditions as established by the setting of the object, electrically operated means for varying the setting of said object, an oscillatable striker adapted intermittently to engage said movable element, a constantly rotating actuator for oscillating said striker, a double throw switch adapted to close automatically in one direction, a cam carried by said actuator adapted intermittently to closesaid switch in the opposite direction, a relay whose circuit is closed when the actuator is moving the striker toward the movable element of the indicating device and the said cam is holding the double throw switch closed, a second relay, a switch in the circuit of said relay which opens upon closing of the circuit of the first relay, said cam being so disposed relatively to the double throw switch that upon further movement of the actuator sufficient to move the striker past the neutral point of the indicating device the cam will have moved away from the double throw switch to permit the latter to close automatically in the opposite direction, to break the circuit of the first relay, a pair of switches closable upon the said de-energization of both relays to close the circuit of said electrically operated means to alter the setting of the object in a direction to restore conditions to normal, and a circuit for the second mentioned relay closed by contact of the striker with the movable element of the indicating device to open the circuit of the electrically operated means, thereby providing for operation of the electrically operated means which is directly proportional to the deviation of the movable element of the indicating device with respect to the neutral point of the indicating device.

3: In mechanism of the class described including an object the setting of which is to be varied, the combination of an indicating device having a movable element which moves to one side of a neutral point on the indicating device when conditions as determined by the setting of the object are abnormal and to the other side of said neutral point when conditions are subnormal, electrically operated means for varying the setting of said object, an oscillatable striker adapted intermittently to engage said movable element, an actuator for the striker, a double throw switch self-closing in one direction, a cam carried bythe actuator adapted intermittently to close the said switch in the opposite direction, a relay, the circuit to which is closed when the striker is at the subnormal side of the neutral point and said cam is holding the double throw switch closed, a second relay, a circuit for the second relay adapted to be closed when the striker and said movable element are in contact at the subnormal side of the said neutral point, a pair of switches closable upon the energization of both relays to close the circuit of the said electrically operated means with the striker and movable element at the subnormal side of the neutral point, and both relays are energized, said cam moving into inoperative position with respect to the said double throw switch when the striker and movable element have moved to the neutral point to open the circuit of the first relay to open the switch controlled thereby and open the circuit of the electrically operated means.

4. Control mechanism comprising a reversible motor; a pivoted indicating element, indicating when the motor is to be operated; an oscillatable pivoted striker element, adapted intermittently to engage the indicating element to effect pivotal movement of the two elements as a unit; a circuit for said motor; contact mechanism in said circuit closed by engagement of said two elements, to close said motor circuit; a magnet carried by one element, the other element having a metal area, the magnet and metal area contacting when the two elements are engaged to prevent chattering and arcing, the pivots of the two elements being offset relatively so that, with the two elements engaged, a wiping action is provided between the two to improve the contact be tween the indicating element and the striker.

5. Control mechanism comprising a reversible motor; a pivoted indicating element, indicating when operation of the motor is desired; an oscillatable pivoted striker element, adapted intermittently to engage the indicating element to effect pivotal movement of the two elements as a unit; a circuit for said motor; contact mechanism in said circuit closed by engagement of said two elements, to close said motor circuit; and a constantly rotating motor for oscillating said striker element.

6. Control mechanism comprising, in combination, a reversible motor; a pivoted indicating element, indicating when the motor is to be operated and in which direction; a pivoted striker arm; a continuously running motor; an arm driven thereby and intermittently engaging the striker arm, to oscillate the same into intermittent engagement with the indicating element; a circuit for said reversible motor; contact mechanism in said circuit closed by contacting of the striker element with the indicating element, with the latter at one side of a neutral position, thereby to close said motor circuit for one direction of rotation of the reversible motor; contact mechanism in said motor circuit controlled by said rotating arm for opening said motor circuit when the striker arm and indicating element have reached said neutral position; another circuit for said motor, to efiect rotation of the same in the opposite direction; contact mechanism in this second circuit controlled by said arm, to close said second circuit when the indicating element is at the side of neutral position opposite to that first mentioned and with the striker moving to neutral position; and a relay, the circuit of which includes the striker arm and indicating element for opening the said second circuit of the reversible motor when the striker arm has moved past neutral position into engagernent with the indicating element.

WALCOTT M. ADAMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,512,008 Otis Oct. 14, 1924 1,586,569 Newman June 1, 1926 1,732,060 Moeller et al Oct. 15, 1929 2,046,676 Dueringer July '7, 1936 2,106,030 Junkins Jan. 18, 1938 2,109,776 Johnson Mar. 1, 1938 

